A conventional braking system is described in German Patent Application No. 196 34 567. This conventional braking system has a decentralized structure in which a pedal unit for forming the command variables, which are a function of the driver's input, optionally a processing unit for the consideration of additional functions, as well as wheel-pair units for the open-loop or closed-loop control of the final controlling elements of the wheel brakes are connected via one or a plurality of communication systems. Furthermore, the braking system is supplied with energy from at least two vehicle electrical systems. In this manner, satisfactory reliability and availability of the braking system is ensured. A "pedal unit" forms setpoint values for the brake control in response to a service braking. An inclusion of a parking brake function is not described.
One of the objects of the present invention is to specify measures for the incorporation of a parking brake function into a decentralized braking system.